Because of the increasing cost of electrical energy, the substitution of initially costlier, but more energy efficient, fluorescent lamps in place of incandescent lamps has become practical. A prime candidate for this substitution is the circular fluorescent lamp primarily because of its compact size when compared with the more typical elongated fluorescent lamp.
Common to most structures employed for this purpose are a central hub which includes a ballast and one or more arms or similar constructions projecting from the hub for holding the lamp.
Exemplary devices of this type are shown in U.S. Pat. Nos. 2,298,961; 2,817,004; Des. 259,961; and 4,278,911.
When the ballast includes a transformer, it is desirable that efficient cooling means be provided to dissipate the heat generated by the transformer. It would also be advantageous to provide means for adequately protecting the transformer. These features are absent from the prior art.